Rotary compressor



Nov. 11, 1930. H. E. BLOOD 1,731,995

ROTARY COMPRESSOR Filed Nov. 26, 1928 2 Sheets-Sheet 1 Z :2; gj

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Nov, 11, 1930. r H. E. BLOOD I 1,781,095

ROTARY COMPRES SOR Filed Nov. 26, 1928 Z Sheats-Sheet 2 Patented Nov. 11, 1930 UNITED STATES PATENT OFFICE HOWARD E. BLOOD, '01 DETROIT, MICHIGAN, ASSIGNOR TO NORGE CORPORATION, A

CORPORATION OF MICHIGAN ROTARY COMPRESSOR Application filed November 26, 192 8. Serial No. 321,778.

This invention relates to rotary compressors adapted to handle gaseous fluids, and is particularly adapted to the handling of refrigerating agents in domestic refrigerating apparatus that is automatically controlled.

It is an object of this invention to provide a compressor of the type described wherein a pressure oiling system feeds oil to the bearing surfaces and provides a sealing pressure acting on the compressor and partition blade thus eliminating mechanical seals with their attendant friction. I

It is also an object of this invention to provide an improved rotary compressor having improved gas cduction and induction passages for a rotary compressor wherein both the cylinder and piston rotate about eccentric axes, the cylinder being free to float at an indeterminate-speed, thus precluding the provision of gas passages in the cylinder. In order to accomplish this object, while providing for an oil pump, I provide an induction passage in the driving shaft and sealed' from the oil pump by a combined seal and thrust bearing which partially supports the rotating parts.

It is another object of this invention to provide an improved rotary compressor submerged in an oil bath subject to the discharge,

pressure generated by the compressor, and having oil passa es leading back of the partition blade to Force the same into contact with the cylinder with a pressure varying in step with the pressure generated by the compressor.

Other and further important objects oi? this invention will be apparent from the disclosures in the specification and accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings:

Figure 1 is a central vertical section through a rotary compressor and its enclosing casing which embodies the features of this invention.

Figure 2 is a fragmentar vertical section with parts in elevation, o the compressor mechanism without the enclosing casing.

Figure 3 is a section on the line IIIIII v pressor to a degree required by the refrigerab ing cycle, the oil is subject to this pressure and transmits it to the exposed o crating parts of the compressor to balance t e'internal pressure generated therein.

The compressor and its driving motor are mounted as an independent unit within the casing 10 and supported in spaced relationship tothe walls thereof in any suitable manner in order that the surrounding oil bath may absorb vibrations set up by the rotating parts.

The compressor is mounted in a base member 14 having an upstanding shell 15 supporting a flange 16 on which is mounted a spider 17 supporting the field core 18 of an electric motor as well as having a bearing hub 19 for a shaft 20 which carries the motor armature. The shaft 20 is the principal moving part of the apparatus, passing through a central lower bearing 21 in the base member and terminating in a threaded portion 22 on which is mounted the impeller 23 of a centrifugaloil pump, the housing for which is formed as a chamber 24 in a member 25 applied to the bottom of the member 14:.

Oil is supplied to the impeller near its hub bymeans of a passage 26 and a downwardly extending inlet pipe 27, and oil is discharged through a peripheral outlet passage 28 and a pipe 29 leading through the bottom closure 11 of the outer casing and eventually back to a return pipe 30 through the outer casing 10 to the member 14 where branch oil passages 31,32 and 33 lead respectively to the bearing hub 19, the compressor proper and the lower bearing 21.

The compressor proper comprises a rotor 34 eccentric to and integral with the shaft 20, the eccentric bein surrounded by a floating cylinder 35 hel concentric with the shaft axis by a bushing 36 seated in a recess 37 in the base member 14, the bushing having a groove 38 in its outer wall in alignment with the oil passage 32 as well as a number of perforations 39 to lead the oil into contact with the outer surface of the cylinder 35.

The cylinder 35 is formed with an internal lower flange 40 the inner portion of which underlies the lower edge of the shaft eccentric to form a seal at the end of the compressing space between the eccentric and the cylinder. This flange rides on a roller hearing 41 in the bottom of the recess 37 The upper end of the cylinder 35 is formed with an outstanding flange 42 the upper surface of which'lies in the same plane as the upper surface of the eccentric on the shaft. An end seal is formed for the upper end of the compression space by adisc 43 slidable but not rotatable relative to the shaft and bearing on the'eccentric and flange, a second similar disc 44 being superimposed thereon.

A partition blade 45 isv mounted in a longitudinal slot 46in the eccentric andshaft, and oil holes 47 crosswise of the shaft lead oil from a vertical passage 48 to the slot 46 behind the blade, the oil being under the discharge pressure in the outer casing, this pressure acting to force the blade outwardly -to maintain sealing contact with the inner surface of the cylinder 35.

The gas tobe compressed is delivered to the body member 14 through a suction pipe 50 opening into a chamber 51 containing a cylindrical screen 52, the chamber being enlarged below the screen to form a valve seat.

53 against which a valve disc 54 seats and is urged thereagainst by a spring 55 mounted on a pilot 56 straddling a vertical passage 57 leading downwardly in the member 25 to a horizontal passage 58 and thence to a vertical passage 59 coaxial with the shaft 20 and a drilled hole 60 therein extending upwardly to the compressor location and meeting an ofiset'inlet passage 61 through the eccentric portion of'the shaft, this passage opening into the compression space adjacent one side of the partition blade.

The junction between the passage 59 in the member 25 and thehole 60 in the shaft is immediately adjacent the oil pump so that the member 25 is counterbored about the mouth of the passage 59 to receive an annular disc 62 of sealing or packing material in the nature of a bearing material, this disc also serving as a thrust bearing supporting the end of the threaded part 22 of the shaft 20, part of the weight of the rotating parts being carried by the disc thus insuring an adequate seal;v The sealing disc naturally wears down into perfect contact with the shaft end thus transferring a portion of the load to the roller bearing 41 previously described.

The gas compressed ahead of the partition blade by the rotation of the eccentric and cylinder 35 is allowed to escape upwardly through a port 63 in the cover disc 43 011. the

gyratory piston type wherein an eccentric inner piston rotates about theaxis of the enclosing cylinder. In the present case the cylinder is .free to float within an enveloping guide bushing, so that the question of relative friction between the piston and cylinder and the cylinder and bushing determines the movement ofthe cylinder. It is immaterial to the compression of the gas as to whether the cylinder rotates or not, the floating mounting resulting in a reduction of the friction and hence, in an increase in the efiiciency of the compressor.

The rotation of the shaft and its eccentric causes the blade therein to sweep through the crescent-shaped compression space thus forming a partition between the suction and compression spaces.- The suction space is fllledby gas flowing in through the pipe 50, screen 52 and the various passages 57, 58, 59, 60 and the port 61, the seal 62 preventing admixture of oil at the point where the gas enters the rotating shaft. The gas is swept ahead of the partition blade and out through the port 63 which rotates in a fixed position relative to the blade 45.

At the same time the lubricating pump maintains an oil circulation through some form of cooler and thence to the bearing surfaces of the shaft and cylinder. The oil bath in which the compressor is submerged is subjected to the discharge pressure from the comder 35.

It will thus be seen that I have produced an improved and simplified rotary compressor unit that can unload itself if excessive pressures develop through the collection of liquid in the compression space or from other causes in which the admixture of oil to the suction side of the compressor is guarded against, and in which the partition blade is urged outwardly by fluid pressure generated by the compressor and hence proportioned to the pressure required for properly sealing the blade at various compressor discharge pressures.

I am aware that many changes may be made, and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I therefore do not purpose limiting the patent granted hereon, otherwise than necessitated by the prior art.

I claim as my invention 1. A compressor comprising an outer casing adapted to contain a body of oil, a co1npressor mounted in said casing and adapted to be submerged in said body of oil, said compressor comprising an eccentric rotor, a floating cylinder having an out-turned u per flange, and an inturned lower flange ma ing sealing contact with the lower surface of the rotor, a sealing disc contacting the upper surface of the rotor and the out-turned upper fiange of the cylinder, means for maintaining said cylinder coaxial with said shaft, an intake passage formed in said shaft, an oil pump mounted on the end of said shaft, and means for sealing said intake passage from said oil pump. 2. A compressor comprising an outer casing adapted to contain a body of oil, a compressor mounted in said casin and adapted to be submerged in said body of oil, said compressor comprising an eccentric rotor, a floatin c linder havin an out-turned u or b 3 7 b flange, and an inturned lower flange ma ng sealing contact with the lower surface of the rotor, a sealing disc contacting the upper surface of the rotor and the out-turned upper flange of the cylinder, means for maintaining said cylinder coaxial with said shaft, an intake passage formed in said shaft, an oil pump mounted on the end of said shaft, and means for sealing said intake passage from said oil pump.

3. A compressor comprising an outer casing adapted to contain a body of oil, a compressor mounted in said casing and adapted to be submerged in said body of oil, said compressor comprising an eccentric rotor, a floating cylinder having an out-turned upper flange, a sealing disc contacting the upper surface of the rotor and said flange, means for maintaining said cylinder coaxial with said shaft, an intake passage formed in said shaft, an oil pump mounted on the end of said shaft, and means for sealing said intake passage from said oil pump.

at. A compressor comprising an outer casing adapted to contain a body of oil, a comressor mounted in said casing and adapted to iie submerged in said body of oil, said compressor comprising an eccentric rotor, a floating cylinder, means for maintaining said cylinder coaxial with said shaft, a partition blade carried by said rotor and engaging said cylinder, means for leading oil back of said blade to force the same outwardly, an intake passage formed in said shaft, an oil pump mounted on the end of said shaft, and means for sealing said intake passage from said oil pump,

5. A compressor comprising a shaft, an eccentric cylindrical rotor formed thereon, an annular cylinder enclosing said rotor and having an internal diameter greater than the diameter of the rotor, said cylinder having an inturned flange closing one end of the space between the rotor and the cylinder, an out-turned flange on the other end of said cylinder, a cover making sealing contact with the rotor and said out-turned flange to com} plete the enclosure of the space between the rotor and the cylinder, a partition blade carried by said rotor and making contact with the cylinder, and a body having a journal for said shaft, there being arecess in said body adapted to maintain said "cylinder concentric to the shaft.

6. A compressor comprising a shaft, an cecentric cylindrical rotor formed thereon, an annular cylinder enclosing said rotor and having an internal diameter greater than the diameter of the rotor, said cylinder having an inturned flange closin one end of the space between the rotor an the cylinder, an outturned flange on the other end of said cylinder, :1 cover making sealing contact with the rotor and said out-turned flange to complete the enclosure of the space between the rotor and the cylinder, a partition blade carried by said rotor and making Contact with the cylinder, and a body having a iournalfor said, shaft, there being a recess in said body adapteld tfo maintain saidcylinder concentric to the s a t.

7 A-compressor comprising an outer cas ing adapted to contain a body of oil, a com" pressor mounted in said casin and adapted to be submerged in said body of oil, said compressor comprising a shaft, an eccentric cylindrical rotor formed thereon, anannular cylinder enclosing said rotor and having an internal diameter greater than the diameter of the rotor, said cylinder having an in turned flange closing one end of the space be tween the rotor and the cylinder, an outturned flange on the other end of said cylinder, :1 cover making sealing contact with the rotor and said out-turned fiangeto complete the enclosure of the space between the rotor and the cylinder, a partition blade carried bysaid rotor and making contact with the cylinder, and a body having a journal for said shaft, there being a recess in said body adapted'to maintain said cylinder concentric to the shaft. 8. A compressor comprising an outer casing adapted to contain a body of oil, a compressor mounted in said casing and adapted to be submerged in said body of oil, said compressor comprising a shaft, an eccentriccylindrical rotor formed thereon, an annular cylinder enclosing said rotor and having an internal diameter greater than the diameter of the rotor, said cylinder having an inturned flange closing one end of the space hetween the rotor and the cylinder, an outturned flange on the other end of said cylinder, a cover making sea1in contact with the rotor and said out-turned fiange to complete the enclosure of the space between the rotor and the cylinder, a partition blade carried v by said rotor and making contact with the cylinder, a body having a journal for said shaft, there being a recess in said body adapted to maintain said cylinder concentric to the shaft, and an oil pump mounted on said shaft adjacent the entrance to said induction passage.

In testimony whereof I have hereunto subscribed my name at Detroit, Wayne County,

Michlgan.

' HOWARD E. BLOOD. 

